Lectins as Promising Therapeutics for the Prevention and Treatment of HIV and Other Potential Coinfections

Mazalovska, Milena; Kouokam, J. Calvin

Considering its clinical importance, the majority of studies assessing antiviral lectins have focused on HIV. However, based on their mechanisms of action carbohydrate-binding agents may target a multitude of enveloped viruses which share the feature of heavily glycosylated proteins on their surfaces. Not surprisingly, anti-HIV lectins have been extensively evaluated for their effects on other enveloped viruses (Table 1) . For instance, Aspidistra elatior lectin (AEL) displays antiviral effects against the enveloped respiratory syncytial virus but also against Coxsackie virus B4, a non-enveloped virus [48] , suggesting that lectins may target other viral components than surface glycoconjugates. This notion was confirmed by the protective effects of GRFT in mice infected with vaginal HPV infection, although more pronounced effects were achieved by the carrageenan-GRFT combination; such anti-HPV activity likely occurs via 6 integrin internalization as shown in vitro [49] . In addition, intraperitoneal GRFT was shown to prevent Japanese encephalitis virus (JEV) entry, both in vitro and in vivo [50] . Mechanistically, GRFT was recently reported to bind to the glycosylated proteins E and prM of JEV [51] . GRFT was assessed in parallel with other potent anti-HIV lectins from algae, namely, CV-N and scytovirin (SVN), and differential inhibitory activities were found against other enveloped viruses such as gammaretroviruses and deltaretroviruses [52] . A few envelope viruses sensitive to lectins are discussed below.